The invention is directed to a control apparatus for turning off an internal combustion engine.
One such control apparatus is disclosed in German Patent Disclosure 39 34 389 A1.
This control apparatus has a fuel injection pump that is supplied with fuel by a feed pump. The control apparatus also has a reversing valve, which can be switched over between a feed position and a shutoff position. In the feed position of the reversing valve, the feed pump aspirates fuel from a tank via a tank line and a suction line, and it pumps it into the suction chamber of the fuel injection pump via a pressure line and a suction line. In the shutoff position of the reversing valve for turning off the engine, the feed pump aspirates fuel from the suction chamber of the fuel injection pump via the connecting line and the suction line and pumps it back to the tank via the pressure line and the tank line.
The reversing valve is embodied as a two-position multiposition valve and has a valve member that is disposed axially displaceably in a valve housing. The valve member has two seat valve closing bodies, each cooperating with a respective one of two valve seats formed in the valve housing and in the two positions establishing the necessary connections of the lines via control conduits as needed.
The valve member is displaceable by an electromagnet that is inserted by its face end into the valve housing, and so the reversing valve has a long structural length. The electromagnet has a separate housing, from which a pin protrudes for actuating the valve member. The reversing valve housing is of cast metal and is made in multiple parts, to enable making the control conduits and assembling the valve member and the electromagnet.
This known reversing valve is thus very complicated and expensive in construction, and many individual parts have to be assembled. Its construction needs to be changed, to make it simpler and less expensive to manufacture.